The present invention generally relates to a washing machine for washing home clothing and more particularly, to a control device for the washing machine, which employs a microcomputer.
In recent years, development of sensor technology and control technology based on a microcomputer such as fuzzy control has enabled more sophisticated and optimum control of washing operation in accordance with soil and quantity of items to be washed. For example, Japanese Patent Laid-Open Publication No. 3-94795 (1991) proposes a washing machine in which washing period can be controlled in accordance with soil of washing liquid. However, in fuzzy control disclosed in this prior art document, an antecedent membership function indicative of magnitude of a signal from a sensor or a consequent membership function indicative of operational quantity to be subjected to fuzzy inference, such as washing period is determined by a designing engineer of the washing machine or experimentally. Thus, in case its user wishes to wash or rinse the items slightly longer than the preset period, the additional washing or rinsing period is set to a predetermined value through manual operation irrespective of a detection signal from the sensor.